Understand the electricity tariffs

It has been a while since I moved to the new place with two power metres in the box.

I was not aware that the rate on one metre (the Controlled Load 1) is much cheaper than the other until the first bill arrived.

However, it took even longer for me to understand why there’s such a big difference and how it encourages the residents to consume the energy wiser.

The controlled load is a tariff dedicated to large, high energy usage appliances and it is metered separately at a much cheaper rate. Only the hot water system is connected to the control load supply in my home, and the rate is only 1/3 of the regular supply.

The only catch is that the controlled load 1 only supplies for some limited hours (10pm – 7am) during the night, which is called non-peak energy demand periods. Why is the power cheaper during night then?

Due to the size and design, most power plants work continuously and steadily all year around, e.g. fossil fuel power station cannot be shut down in the night and restarted in the morning, a wind farm generate power whenever there’s wind, therefore the electricity power is generated in a stable rate day and nights. However, the consumption of energy has clear daily pattern as most offices, factories and homes stop using power in the night.

Electricity is the most convenient form of power supply but a shortcoming is that it cannot be easily stored. The coal can be burnt because it’s essentially a block of energy from ancient ages, once the coal is burnt in the power plant, the inner energy is released and transformed into the form of electricity. However, there are limited methods to transform the energy of electricity into other form, such as converting it back to a block of coal.

Battery and hydropower plant are two common ways of storing abundant electricity, in the form of chemical and potential energy respectively, though both are limited by capacity and expenditure issue.

Instead of wasting the already generated power overnight, the hot water system in our home can convert the power into the heat energy and store it as hot water for the use during the day, that’s why the controlled load tariff is applied to encourage people to utilise the power during off-peak period and use the cheap rate as incentive.

Although one may select the controlled load purely for the financial benefits, the usage of controlled load has somehow contributed to a sustainable usage of the power. It would be more efficient if this is used together with other system such as the Tesla Powerwall.

https://www.canstarblue.com.au/energy/electricity/controlled-load-tariff-can-save-money/